Dispenser for liquids



June 5, 1956 E. c. WRIGHT 2,748,767

DISPENSER FOR LIQUIDS Filed Jan. 9, 1955 2 Sheets-Sheet l June 5, 1956 E. c. WRIGHT 2,748,767

DISPENSER FOR LIQUIDS Filed Jan. 9, 195a 2 Sheets-Sheet 2 [ht/en/r Ernesf Char/e5 Wr/y/r/T United States PatentO DISPENSER FOR LIQUIDS Ernest Charles Wright, New Haw, Weybridge, England Application January 9, 1953, Serial No. 330,411

2 Claims. (Cl. 128-218) The invention relates to improvements in applicators or dispensers for delivering a single dose or a multi-dose of a liquid. 7

By the present invention there is provided an applicator or dispenser working on a pistol type principle for delivering a single dose or a multi-dose of a liquid, and comprising a body part having a holding device adapted to receive a removable liquid container, means at one end of said device through which the liquid is delivered when expelled from said container, the liquid in said container being impelled forward under the impetus of control means actuated by a trigger action.

The invention is well suited for use in the medical or surgical or veterinary sciences, but it is to be understood it may be applied to other purposes and is not confined to the above sciences.

The container may be of any suitable form, and when used in the sciences would normally be what is known as sterile containers, which may be in the form of cartridges, phials or bottles. The term cartridge is intended to include any suitable form of container.

One of the advantages gained by the pistol type applicator or dispenser according to the invention is that the applicating pressure is in the opposite or reverse direction to that of the flow of the liquid, so that when the applicator or dispenser is used in medical or surgical work as an injection instrument, for example, hypodermic injection, the pressure is in the opposite direction to the needle injection, thus automatically preventing the tendency for the needle to move forward during injection.

As stated the applicator or dispenser may be so designed or arranged for single or multi-dose dispensing or both. By way of example only it may be stated in very general terms and not in any way in a limiting sense that approximately 20 shots would be used for veterinary injections, or 6 shots for dental injections, and single shot operation for medical or surgical applications.

There are various refinements or additions or modifications which may be incorporated in the applicator or dispenser and these are referrd to later.

The applicator or dispenser is hereinafter described with reference to hypodermic injection, but it will be understood this is by way of example only, and is not to be considered as a limitation of the scope of the invention.

The accompanying drawings illustrate examples of the carrying into effect of the invention.

In the drawings:

Fig. l is a side elevation,

Fig. 2 a side elevation with a side plate of the body removed and the ram positioned about mid-way in the cartridge.

Fig. 3 a side elevation again with the side plate removed but with the ram and allied parts moved to the backward position,

Fig. 4 a view of the rack and ram component,

Fig. 5 a sectional view of a ferrule member forming the front component of the cartridge holder,

Fig. 6 a view of a removable locking member,

Fig. 7 is a view showing the back component of the cartridge holder.

The body 1 is of pistol-like design. Mounted on the body is a holding device consisting of two members 2 and 3. Between these members a cartridge 4 is held. This cartridge is of any suitable kind and in the constructional example being described would be a sterile container. The cartridge is held so as to be readily inserted and removed from the holding device.

One way of holding the member 2 to the body is by means of a downwardly extending lip 5 which enters a groove 6 in the body, the lip at one end 7 being rounded to seat in a correspondingly shaped end part of the groove, the other end 8 of the lip being so formed as to interengage with a locking projection 9 on a removable member 10 passing through a slot 11 in the side of the body. Thus the member 2 can be readily detached from the body for sterilization.

The member 2 is fitted with a ferrule or collet 12 so that a hypodermic needle of the straight through type may be used, this needle piercing the cap of the cartridge automatically upon insertion. The needle holding part could be so shaped that it automatically presented the correct angle for inserting the needle into say the vein for injection.

The member 3 is fixed to the body 1 and is of tubular form. Within the bore thereof is a loose internal sleeve 13. A spring 14 bears against this sleeve and serves to partially project the sleeve from the bore. The other end of the spring bears against the metal part of a composite disc 15 the other part of the disc being of a resilient material. The disc 15 bears against the flange of a collar or cap 16 which is screwed on to the member 3.

The holding device may be adaptable for cartridges of different sizes both as to length and diameter.

The ejection of the fluid from the cartridge is by means of a rubber piston or displacer 17 within the cartridge which is moved forward by a ram 18. At the other end of the ram rod 13a is a slide block 19.

The lower end of the slide block 19 is secured to a rack member 20 working in a slot 20a in the body 1. To impart forward movement of the ram or piston 18 within the cartridge, the rack is moved forward tooth by tooth by means of a pawl 21 pivoted to a trigger 22, the latter being pivoted to the body 1 at 23. A spring 24 returns the trigger to normal position when this is released and thus withdraws the pawl from the rack teeth. A spring 24a also assists in the withdrawal of the pawl.

The ram and its associated piston are positively locked against backward movement in each position of forward movement by a locking pawl 25, on a sliding member 26 having a finger grip 27 at its lower end. The member 26 has a pivoted pawl 28. To this pawl the spring 24 is secured and also a spring 29 the other end of which is attached to the member 26 near to its lower end.

In some cases, particularly for surgical, medical and veterinary uses, in the design of the operating rack provision is made for suitable back-lash to accommodate the expansion of the rubber piston which occurs when pressure ceases to be applied. Without this calculated back-lash the expansion of the rubber piston would cause a drip at the needle point.

The rear sliding actuating device may be so arranged that it can be calibrated for length, so as to obtain a correct starting position.

When the sliding member 26 is so positioned that the locking pawl 25 is in engagement with the rack 20, the ram and its associated parts are locked against backward movement, but on completion of a full forward movement to remove the cartridge, or in some cases should it be desired to remove a partly used cartridge before a full forward movement is completed the ram can be withdrawn to the full rear position by a manual release. This is done by moving the finger grip 27 from the full position shown in Fig 2 to that shown in Fig. 3. The effect of this is to pull down the sliding member 26 against the pull of the springs 24 and 29 and thereby release the pawl 25 from the rack teeth. When this has been done the rack member 20 is freed to move backwardly and with it the ram 18. This backward movement is done by a grip of the slide block 19.

The cartridge is held in position between the spring loaded internal sleeve 13 of the member 3 at one end and the wall or abutment 30 of the member 2. To insert or withdraw a cartridge the sleeve 13 is drawn back against the spring 14 by a backward over-run of the ram 18 colliding with an internal collar 31 on the sleeve 13.

The particular construction illustrated by Figs. 1 to 6, is for multi-dose dispensing, but the invention is equally applicable for single-shot operation. type the ratchet or rack and pawl may be replaced by a suitable cable device or a non-elastic fluid device, or a ball loaded channel device to impart the forward movements of the operating ram.

The applicator or dispenser can be made of metal, plastic or other suitable material and produced in laminated form or from suitable die castings or injection mouldings.

A caliper or other suitable measuring or registering device may be detachably or otherwise attached to the body or barrel or handle.

It will be apparent that the invention can be variously modified and changed within the scope of the appended claims.

I claim:

1. A dispenser for the hypodermic injection of liquids In the single-shot comprising, the combination of, a pistol-like body, a cartridge-holding device mounted on the top of said body and having two spaced tubular supports arranged and positioned to hold a cylindrical cartridge for liquids there between, one of said supports being fixed to said body and the other support being slidably mounted on said body, a rack slidably mounted in a slot in said body, a piston fixed to said rack and positioned to slide inside one end of a cartridge when held between said supports and upon movement of said rack, a pawl mounted on said body and positioned to engage and advance said rack, a springloaded trigger mounted on said body and pivoted to said pawl and a collet chuck on said slidable support for holding a hypodermic needle through which liquid will be ejected from said cartridge upon movement of said piston.

2. A dispenser as claimed in claim 1 in which a second spring'loaded pawl is slidably mounted on said body in normal engagement with said rack and a spring loaded lever is pivotably mounted on said body with its free end protruding from the lower part of said body and the other end pivoted to said second pawl to withdraw it from engagement with said rack.

References Cited in the file of this patent UNITED STATES PATENTS 2,417,140 Swanson Mar. 11, 1947 2,475,939 Applezweig July 12, 1949 2,624,338 Moore et al. Jan. 6, 1953 2,645,224 Beebe July 14, 1953 FOREIGN PATENTS 361,789 Germany Oct, 19, 1922 

